Pressure vessel safety lock apparatus

ABSTRACT

The present disclosure provides a locking device for restricting access to a hatch of a pressure vessel, and, more specifically, a locking device that is responsive to the internal pressure in the pressure vessel so as to minimize the ability of one to open the hatch while the vessel is still pressurized. In some embodiments, the locking device comprises first and second portions of the locking device configurable between an open and a closed configuration and a pressure-responsive locking member in fluid communication with an outlet port of the pressure vessel and arranged to automatically retain the first and second portions in the closed configuration when the pressure inside of the pressure vessel is above a predetermined threshold, wherein in the closed configuration the first and second portions restrict manipulation of the hatch and/or a locking mechanism of the hatch.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 13/598,873,filed Aug. 30, 2012, which claims the benefit of U.S. ProvisionalApplication No. 61/532,243 filed Sep. 8, 2011, which are herebyincorporated by reference.

FIELD OF THE INVENTION

Aspects of the present disclosure deal with locking apparatus onpressure vessels.

BACKGROUND OF THE INVENTION

Pressure vessels for various purposes such as abrasive blastingtypically have a fill hatch which is closed and locked when the vesselis under pressure, but which can be opened to add material to thepressure vessel and/or for interior inspection and work. While suchhatches typically have locking mechanisms, there can be safety concernsif the locks are prematurely disengaged while the vessel is stillpressurized. The present apparatus provides an automatic safety lockresponsive to internal pressure in a pressure vessel or pressurized tankto minimize the ability to prematurely open the hatch.

SUMMARY OF THE INVENTION

The present apparatus provides an automatic safety lock responsive tointernal pressure in a pressure vessel or pressurized tank to minimizethe ability to open the hatch before the internal pressure has droppedbelow a desired threshold. In some aspects, the present disclosureprovides a locking device for restricting access to a hatch of apressure vessel, comprising: a first half portion and a second halfportion mounted to each other at rearward ends and configurable betweenan open configuration and a closed configuration wherein in the closedconfiguration the first half portion and the second half portion arearranged to prevent the hatch of a pressure vessel from being opened; apressure-responsive locking member comprising a cylinder assembly havinga body portion and a reciprocating cylinder rod that is extendable froma retracted position to an extended position; wherein thepressure-response locking member fluidly communicates with an outletport of the pressure vessel; and wherein the pressure-responsive lockingmember is arranged to automatically extend to retain the first andsecond half portions in the closed configuration when the pressureinside of the pressure vessel is above a predetermined threshold. Insome embodiments, the locking device further comprises a latch platethat is pivotally mounted to said first half portion and configurablebetween an unlatched position and a latched position; wherein thelatched position of the latch plate is arranged to retain the first andsecond half portions in the closed configuration; and wherein thepressure-responsive locking member is arranged to retain the first andsecond half portions in the closed configuration by preventing the latchplate from changing to an unlatched position.

In some embodiments, the present disclosure teaches a locking device forrestricting access to a hatch of a pressure vessel, comprising: a firstportion and a second portion coupled to each other and configurablebetween an open configuration and a closed configuration wherein in theclosed configuration the first portion and the second portion arearranged to prevent the hatch of a pressure vessel from being opened; apressure-responsive locking member comprising a cylinder assembly havinga body portion and a reciprocating cylinder rod that is extendable froma retracted position to an extended position; a latch plate pivotallymounted to the first portion and configurable between an unlatchedposition and a latched position; wherein the latched position of thelatch plate is arranged to retain the first and second portions in theclosed configuration; wherein the pressure-response locking memberfluidly communicates with an outlet port of the pressure vessel; andwherein the pressure-responsive locking member is arranged toautomatically extend to retain the first and second portions in theclosed configuration when the pressure inside of the pressure vessel isabove a predetermined threshold. In some instances, the first and secondportions are pivotally mounted to each other. Additionally, oralternatively, the first and second portions can be arranged to encirclethe hatch of the pressure vessel in the closed configuration.

In some instances, the present disclosure describes a locking devicemountable to a hatch of a pressure vessel, comprising: a first halfportion and a second half portion mounted to each other at rearward endsand configurable between an open configuration and a closedconfiguration wherein in the closed configuration the first half and thesecond half are arranged to prevent the hatch of a pressure vessel frombeing opened; a pressure-responsive locking member comprising a cylinderassembly having a body portion and a reciprocating cylinder rod that isextendable from a retracted position to an extended position; and alatch plate pivotally mounted to the first half portion and configurablebetween an unlatched position and a latched position; wherein thelatched position of the latch plate is arranged to retain the first andsecond half portions in the closed configuration; wherein the first andsecond half portions are pivotally mounted to each other and arearranged encircle the hatch of the pressure vessel in the closedconfiguration; wherein the pressure-response locking member fluidlycommunicates with an outlet port of the pressure vessel; and wherein thepressure-responsive locking member is arranged to automatically extendto retain the first and second half portions in the closed configurationwhen the pressure inside of the pressure vessel is above a predeterminedthreshold.

Further forms, objects, features, aspects, benefits, advantages, andembodiments of the present invention will become apparent from adetailed description and drawings provided herewith.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective schematic view of a locking apparatus andpressure vessel system according to an embodiment herein.

FIG. 2 is a perspective schematic of an upper portion of the pressurevessel of FIG. 1.

FIG. 3A is a perspective view of the system of claim 1 with the lockingapparatus in an open portion.

FIG. 3B is a perspective view of the system of claim 1 with the lockingapparatus moved away from the hatch.

FIG. 4 is an upper, perspective view of the locking apparatus of FIG. 1.

FIG. 5 is a left view of the locking apparatus of FIG. 1.

FIG. 6 is a top view of the locking apparatus of FIG. 1.

FIG. 7 is a right, lower view of the locking apparatus of FIG. 1.

FIG. 8 is a right view of the locking apparatus of FIG. 1.

FIG. 9 is a front view of the locking apparatus of FIG. 1 with thelocking plate removed for illustration purposes.

DESCRIPTION OF PREFERRED EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, such alterations and furthermodifications in the illustrated device, and such further applicationsof the principles of the invention as illustrated therein beingcontemplated as would normally occur to one skilled in the art to whichthe invention relates.

Pressure vessels for various purposes such as abrasive blastingtypically have a fill hatch which is closed and locked when the vesselis under pressure, but which can be opened to add material to thepressure vessel and/or for interior inspection and work. In the drawingsprovided, the top of a pressure vessel or tank is shown with a hingedhatch which can be locked in a closed position using a set of cam lockdevices positioned around the periphery of the hatch. In many instances,the cam lock devices used to lock the hatch in a closed position areoperated by rotating levers of the cam lock devices away from the hatch.While hatches of pressure vessels typically have locking mechanisms,there can be safety concerns if the locks are prematurely disengagedwhile the vessel is still pressurized.

Embodiments of the present disclosure comprise an apparatus thatprovides an automatic safety lock responsive to internal pressure in apressure vessel or pressurized tank to minimize the ability to open thehatch before the internal pressure has dropped below a desiredthreshold.

In some embodiments of the present disclosure, the safety apparatusincludes at least two portions mounted and/or coupled to each other andconfigurable between an open configuration and a closed configuration.For example, the safety apparatus may include semi-circular pieces whichare hinged at one side, such as at rearward ends. The semi-circularpieces can be placed around the hatch in a “clam shell” arrangement andlocked together at their non-hinged ends to secure the clam shell inplace. When in place, the clam shell physically prevents the cam lockingdevice levers from being moved into an unlocked position and/or preventsthe hatch from being opened.

As one locking mechanism, the clam shell can include aligned holes on alatch plate and flange of a semi-circular piece and/or aligned holes onflanges of the semi-circular pieces which can be locked together using apadlock or a tag out device to prevent or warn against opening of theclam shell other than by an authorized, properly trained person.

A second locking mechanism includes a pressure actuated cylinderpositioned on and/or behind a latch plate capable of retaining theportions of the clam shell in a closed configuration. In some instances,the pressure actuated cylinder is fluidly coupled to the interior volumedefined by the pressure vessel. For example, the cylinder can be fed bya pressure hose or line from an output port of the pressure vessel sothat the pressure in the line corresponds to the pressure in the vessel.Preferably, when the pressure inside the vessel and line exceeds aselected threshold, such as one pound per square inch (1 PSI) thecylinder rod is in or moves to an extended position, and engages a pairof openings in the latch plate and on the clam shell to prevent thelatch plate from being opened to unlock the clam shell. When thepressure in the vessel is below the desired threshold, the cylinder rodis retracted and disengages from the latch plate and clam shell to allowthe clam shell to be opened, if there are no other locking members suchas a manual locking member (e.g., a padlock) locking the portions of theclam shell together. In some instances, a biasing member is used toautomatically retract and disengage the cylinder rod from the latchplate.

An example embodiment of the safety lock apparatus is illustrated inFIGS. 1-9. FIGS. 1-3B schematically illustrate system 10 includinglocking device 50 and the top portion of a pressure vessel such as tank20. Tank 20, as illustrated by itself in FIG. 2, includes tank body 22and a hatch 30, for example on the upper portion. Hatch 30 is typicallyhingedly mounted to tank body 22 and when closed can be locked in placewith locking mechanisms 34 such as cam lever arm arrangements. Tank body22 includes an outlet port or fixture 24 in communication with theinternal pressure of tank 20.

Locking device 50 is illustrated in FIGS. 1, 3A and 3B as a clam shellarrangement that is configurable between an open configuration and aclosed configuration and which is capable of encircling hatch 30 andlocking mechanisms 34 when closed. In the closed position of FIG. 1,locking device 50 inhibits hatch 30 from being unlocked or opened. Whendesired, locking device 50 can be unlocked and opened into the openposition to be moved away from hatch 30 as illustrated in FIGS. 3A and3B, allowing access to unlock and open the hatch.

Optionally yet preferably, an elongate tethering member, such as chain66, is attached to locking device 50. In some instances, the elongatetethering member extends from a first portion to a second portion of theclam shell arrangement. In some instances, the apparatus is arranged sothat the locking device and elongate tethering member, e.g., chain 66,encircle hatch 30 even when the clam shell is in the open position, andchain 66 retains locking device 50 from falling or sliding off the topof tank 20.

Shown in further detail in FIGS. 4-9, locking device 50 is formed of aclam shell arrangement having two semicircular halves 52 and 54 whichare pivotally mounted to each other at their rearward ends, for exampleusing hinge pins 60. Each half includes a lower inward extending flange56 and an upper inward extending flange 58 which help enclose hatch 30and prevent undesired removal of locking device 50 from the hatch. Thelocking device halves preferably include handles 62 to assist a user inpulling the forward ends together or apart. Handles 62 are not shown inall figures for ease of reference.

The locking device halves 52 and 54 may also include cut out portions 55to allow the device to be mounted in selected positions to provideoptimal access for an operator, as well as to facilitate viewing ofhatch 30 and locking mechanism 34 and/or to reduce the overall weight ofdevice 50. In some instances, cut out portions 55 can be arranged toreceive portions of locking mechanisms 34 so as to limit relativemovement between device 50 and hatch 30, such as rotational movement ofdevice 50 around the hatch 30.

In some instances, the forward ends of halves 52 and 54 preferablyinclude matching forward flanges 64 which meet in a complimentaryarrangement when the locking device is in the closed position.Optionally, one or more alignment guides such as pin 65 (see FIG. 9) caninteract between the two forward flanges 64 to assist in ensuring properalignment. Also, in some embodiments, ends of the elongate tetheringmember, such as the two ends of chain 66, are mounted to the two halves52 and 54 adjacent the lower edges of flanges 64.

In some embodiments, device 50 comprises a locking or latch plate 70,that is arranged to retain the first and second portions of the clamshell arrangement in a closed configuration. For example, latch plate 70can be positioned on the first or second portion of device 50 oppositeof the hingedly coupled ends. In some embodiments, latch plate 70preferably is pivotally mounted to half 52 via pivot pin 72.

Latch plate 70 includes a vertical front surface and is shown withsubstantially horizontal upper and lower plate sides. Optionally butpreferably, latch plate 70 is biased to a closed position (seen ascounterclockwise around pin 72 in FIG. 4) with a biasing member such asspring 74. In some instances, latch plate 70 includes proximal end 76adjacent half 52 and distal end 78 which extends and overlaps with half54 when the locking device is in the closed position.

In some embodiments, latch plate 70 includes one or more notches such aslocking slots 80 in the upper and lower plate sides which receive andengage forward flanges 64 of the first and second portions of the clamshell arrangement, such as halves 52 and 54, when plate 70 is in theclosed position and the first and second portions of the clam shellarrangement are in the closed configuration. Slots 80 have opposingsides parallel to and engaging flanges 64 that prevent separation of theflanges and thus prevent opening of locking device 50 when the latchplate is in the closed position. When latch plate 70 is in the openposition (moved clockwise around pin 72 in FIG. 4), slots 80 aredisengaged from forward flanges 64, allowing halves 52 and 54 to bepivotally opened and closed. Optionally, the inner facing edges of theside plates along distal end 78 can be tapered to assist the sliding offorward flange 64 on half 54 into position and into slot 80 when lockingdevice 50 is being moved to the closed position. Latch plate 70 ispreferably biased to the closed position by spring 74 on pin 72 so as toautomatically engage forward flanges 64 and lock the first and secondportions of the clam shell into the closed configuration.

In some instances, the locking device comprises multiple locking points,such as one for a pressure-responsive locking member and one for amanual locking member. In the illustrated embodiment, a portion ofdevice 50, such as half 54, includes a tab portion which protrudesforward and defines manual locking hole 69. In the closed position,manual locking hole 69 extends over and is aligned with manual lockinghole 84 defined in the upper side plate of distal end 78. When desired,a manual locking piece such as a padlock, a tamper resistant tag, abolt, a wire, zip tie or similar piece can be inserted through manuallocking holes 69 and 84 to prevent plate 70 from being moved to an openposition. The manual locking piece is preferably selectively removableby a system operator when desired. In preferred embodiments a manuallock is used in addition to the pressure operated lock discussed below,but optionally the pressure operated lock can be used without a manuallock.

Similarly, the locking device may have a locking point for thepressure-responsive locking member. For example, half 52 includes a tabportion extending forward over proximal end 76 of plate 70 and defininga cylinder lock hole 68. Cylinder lock hole 68 is aligned with acylinder lock hole 82 defined in the upper side plate of proximal end 76of plate 70 when plate 70 and halves 52 and 54 are in the closedposition. In some instances, however, cylinder lock hole 68 is alignedwith a cylinder lock hole of half 54 when the halves 52 and 54 are inthe closed configuration. Mounted below and in alignment with thecylinder locking holes is cylinder assembly 90, illustrated as mountedto the inner surface of distal end 76, between plate 70 and half 52.Cylinder assembly 90 and cylinder lock holes 68 and 82 form a pressureactivated locking apparatus.

In several embodiments, cylinder assembly 90 includes body portion 94mounted to distal end 76 and an internal, reciprocating cylinder rod 96.Cylinder rod 96 includes an upper locking end 98, which optionallyincludes a protective cap. Pressure input line 92 extends from a firsttank end in pressurized communication with the volume defined by tank20, for example via port 24, to a second end attached to cylinder body94. When pressure is applied through input line 92 and exceeds a setthreshold amount, rod 96 extends, i.e. translates upward, from body 94so that the rod 96 and locking end 98 extends into and/or through bothcylinder locking holes 68 and 82. Preferably cylinder assembly 90 isinternally biased to return rod 96 to its lowered or disengaged positionwhen the pressure supplied through input line 92 is below the selectedpressure threshold. In the extended position, rod 96 and locking end 98prevent plate 70 from being rotated into an open position andcorrespondingly prevents halves 52 and 54 from being moved to an openposition. Directional references herein, such as upward or downward, areexamples not intended to limit the orientation of other embodiments.

In operation, locking device 50 can be opened and disengaged from hatch30 when access is desired to tank 20, generally when the pressure vesselis at atmospheric pressure. Upon closing and locking of hatch 30,locking device 50 is arranged so that halves 52 and 54 encircle hatch 30and in the closed position the halves prevent unlocking and opening ofhatch 30. When the halves are moved to the closed position, forwardflanges 64 of halves 52 and 54 abut and are preferably aligned with eachother. In pressing the halves together, the proximal end 78 of plate 70extends over the forward portion of half 54 while plate 70 is rotated toan open or partially open position against the biasing of spring 74.When forward flanges 64 are fully abutted and aligned, plate 70 isrotated to the closed position, capturing flanges 64 within lockingslots 80. An operator may then use a manual locking mechanism to lockplate 70 into the closed position through aligned manual locking holes84 and 69.

Pressure may then be introduced into tank 20 via pressure supply means(not shown). As pressure is supplied to and builds within tank 20,pressure builds through outlet port 24 which is preferably connected toinput line 92. Input line 92 carries the pressure to cylinder assembly90. When the tank pressure exceeds a preset threshold, such as 1 psi,the pressure causes cylinder rod 96 to extend from cylinder body 90 suchthat rod 96 and locking end 98 engage cylinder locking holes 82 and 68.This provides a pressure responsive locking function that preventsunlocking of plate 70 and thus prevents unlocking of device 50.Operations using the pressurized vessel or tank can then be commenced asdesired for an appropriate purpose. Locking device 50 operates toprevent opening of hatch 30 while tank 20 is under pressure eitherduring use or prematurely during a venting process.

The manual locking piece is preferably only removed when pressure insidethe tank is at a safe condition and preferably by an authorized andappropriately trained person. However, to avoid accidents if the manuallocking device is removed prematurely, cylinder assembly 90 provides anautomated locking device which is directly responsive to pressure insidethe tank. Cylinder 90 operates to effectively automatically lock andunlock locking device 50 and prevents premature unlocking of the device,even if the manual locking device has been removed, so long as thepressure in the tank exceeds the set threshold.

Advantageously, cylinder 90 can signal when the internal pressure dropsbelow the desired threshold by the retraction of locking end 98.Optionally, locking end 98 may include indicia to signal the position oflocking end 98 more easily, for example with a red or orange cap whichis visible above or through locking hole 68 when locking end 98 isextended.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and described and that allchanges and modifications that come within the spirit of the inventionare desired to be protected.

1-20. (canceled)
 21. A device for a hatch of a pressure vessel lockedwith cam locks, comprising: a first half portion and a second halfportion mounted to each other at rearward ends and configurable betweenan open configuration and a closed configuration wherein in said closedconfiguration said first half portion and said second half portion arearranged to extend circumferentially around the hatch of the pressurevessel and the cam locks to prevent handles of the cam locks from beingmoved into an unlocked position; and a pressure-responsive lockingmember comprising a cylinder assembly having a body portion and areciprocating cylinder rod that is extendable from a retracted positionto an extended position; wherein said pressure-responsive locking membercommunicates with an outlet port of the pressure vessel and is in directfluid communication with pressure inside the pressure vessel; andwherein said pressure-responsive locking member is arranged toautomatically extend to retain said first and second half portions insaid closed configuration when the pressure inside of the pressurevessel rises above a predetermined threshold; and wherein the cam locksare positioned between said hatch and said first and second halfportions when said first and second half portions are in said closedconfiguration around the hatch and cam locks.
 22. The device of claim21, wherein: said first and second half portions are pivotally mountedto each other.
 23. The device of claim 21, further comprising: a latchplate pivotally mounted to said first half portion and configurablebetween an unlatched position and a latched position; wherein saidlatched position of said latch plate is arranged to retain said firstand second half portions in said closed configuration; and wherein saidpressure-responsive locking member is arranged to retain said first andsecond half portions in said closed configuration by preventing saidlatch plate from changing to an unlatched position.
 24. The device ofclaim 23, wherein: said latch plate is biased into said latchedpositioned.
 25. The device of claim 23, further comprising: a firstflange of said first half portion arranged to abut a second flange ofsaid second half portion when said first and second half portions are insaid closed configuration; and a notch defined by said latch plate andarranged to receive said first and second flanges.
 26. The device ofclaim 23, wherein: said pressure-responsive locking member is mounted tosaid latch plate.
 27. The device of claim 23, wherein: saidpressure-responsive locking member is shielded behind said latch plate.28. The device of claim 21, further comprising: a biasing member biasingsaid reciprocating cylinder rod into said retracted position when thepressure inside of the pressure vessel falls below the predeterminedthreshold.
 29. The device of claim 21, further comprising: a firstlocking point engaged by said reciprocating cylinder rod of saidpressure-responsive locking member; and a second locking point arrangedfor engagement by a manual locking member to retain said first andsecond half portions in said closed configuration.
 30. The device ofclaim 21, further comprising: an elongate tethering member extendingfrom said first half portion to said second half portion; wherein saidelongate tethering member in combination with said first and second halfportions encircles the hatch to retain said locking device in proximityto the hatch when said first and second half portions are in said openconfiguration.
 31. The device of claim 30, wherein: said elongatetethering member is a flexible member.
 32. The device of claim 30,wherein: said elongate tethering member includes a chain.
 33. The deviceof claim 21, wherein: when in said closed configuration around thehatch, said first and second half portions are positioned radiallyoutward from the hatch and the cam locks.
 34. The device of claim 21,wherein: said first and second half portions are configured to operatebetween said open configuration and said closed configuration separatelyof the operation of the cam locks.
 35. The device of claim 21, wherein:said first and second half portions extend underneath the cam locks whenin the closed configuration to prevent removal of the first and secondportions from the pressure vessel.
 36. The device of claim 21, wherein:said first and second half portions are removable from the pressurevessel when in the open configuration.
 37. The device of claim 36,wherein: a flexible hose extending from a first end to a second end, thefirst end coupled to said pressure-responsive locking member and thesecond end coupled to the outlet port of the pressure vessel.
 38. Adevice for a hatch of a pressure vessel locked with cam locks,comprising: a first half portion and a second half portion mounted toeach other at rearward ends and configurable between an openconfiguration and a closed configuration wherein in said closedconfiguration said first half portion and said second half portion arearranged to extend circumferentially around the hatch of the pressurevessel and the cam locks to prevent handles of the cam locks from beingmoved into an unlocked position; and a pressure-responsive lockingmember comprising a cylinder assembly having a body portion and areciprocating cylinder rod that is extendable from a retracted positionto an extended position; wherein said pressure-responsive locking membercommunicates with an outlet port of the pressure vessel and is in directfluid communication with pressure inside the pressure vessel; whereinsaid pressure-responsive locking member is arranged to automaticallyextend to retain said first and second half portions in said closedconfiguration when the pressure inside of the pressure vessel risesabove a predetermined threshold; and wherein said first and second halfportions are configured to operate between said open configuration andsaid closed configuration separately of the operation of the cam locks.39. The device of claim 38, wherein: wherein said cam locks arepositioned between said hatch and said first and second half portionswhen said first and second half portions are in said closedconfiguration around the hatch and cam locks.
 40. The device of claim38, wherein: said first and second half portions extend underneath thecam locks when in the closed configuration to prevent removal of thefirst and second portions from the pressure vessel.